Methods : Eighty liver cancer patients are included in the study. They are systematically computerized and randomized into two groups - an experiment or video group (N 40) and a control or Handbook group (N = 40). A 40-item exam is performed to test the patients' knowledge before (x score), after (y score) and 60 days (z score) after the procedure. The 15-min study was taken in an isolated room. The points of interest are the effectiveness of medias on learning achievement and relative growth of knowledge. The relative growth of knowledge (G1, G2 score) was calculated as follows: